Interlocking relay



Jan. 9, 1940. FEREDAY 2,186,670

INTERLOCKING RELAY Filed July 19, 1939 3 Sheets-Sheet l Jan. 9, 1940. FEREDAY 2,186,670

INTERLOCKING RELAY Filed July 19, 1939 3 Sheets-$heet 2 ZZIbredaq,

Jan. 9, 1940. F. T. FEREDAY INTERLOCKING RELAY Filed July 19, 1939 3 Sheets-Sheet 5 Patented Jan. 9, 1940 UNITED STATES PATENT OFFICE 8 Claims.

This invention relates to interlocking relays such as are used for the control of highway crossing signals, and has generally in View to provide an interlocking relay embodying an interlocking mechanism having various improved features as compared with the interlocking mechanisms of known interlocking relays.

An interlocking relay is simply two ordinary neutral relays which an interlocking mechanism therebetween, whereby the operation of each is affected by the operation of the other to the end that proper control of flashing lamps, bells, wigwag signals, stop signs, gate lamps, automatic crossing gates and the like is efiected. Heretoiore, such relays have caused considerable trouble because of failure, for one reason or another, of their interlocking mechanisms. The construction of some mechanisms is such that their successful operation is dependent upon overcoming considerable friction. Such mechanisms sometimes fail because of excessive friction. Other mechanisms are frail and soon wear, bend or break in service with consequent failures. Still other mechanisms are very intricate and 25 require very delicate adjustments which are diflicult to maintain in service, with the consequence that they frequently fail due to loss of adjustment of their parts.

Accordingly, the present invention has more particularly in view to provide an interlocking relay embodying an interlocking mechanism which is of simple, strong, sturdy and durable construction and which, in operation, is subjected to very little friction, whereby it is unlikely to fail in service due to causes as enumerated which have resulted in failures of prior interlocking mechanisms. In short, the primary object of the present invention is to provide an interlocking relay which remains thoroughly re- 40 liable and enicient in operation over long periods of time without attention.

Another object of the present invention is to provide an interlocking mechanism embodying novel adjustment means which are easy to ad- 45 just and which reliably maintain their adjustnients.

With the foregoing and other objects in View, which will-become more fully apparent as the nature of the invention is better understood, the same consists in the novel features of construction, combination and arrangement of parts as will be hereinafter more fully described, illustrated in the accompanying drawings and defined in the appended claims.

In the accompanying drawings, wherein like characters of reference denote corresponding parts in the different views:

Figure 1 is a diagrammatic view illustrating a simple relay installation for the control of a lamp flashing mechanism.

Figure 2 is a longitudinal section through an interlocking relay constructed in accordance with one practical embodiment of the invention.

Figure 3 is a transverse section through the relay shown in Fig. 2.

Figure 4 is an enlarged section through one of the switch arms of the relay shown in Figs. 2 and 3.

Figure 5 is an enlarged section through the mounting means for one of the locking arms. of the interlocking mechanism of the relay shown in Figs. 2 and 3.

Figure 6 is a section on the line 6-6 of Fig. 5.

Figures 7 through 11 are front elevations of the present interlocking mechanism illustrating different operative positions of the locking arms the locking dogs of said mechanism; and

Figure 12 is a perspective view of the mounting means for the locking dogs of the present interlocking mechanism.

Referring to the drawings in detail, first with particular reference to the explanatory installation illustrated in Fig. 1, A designates a railroad track which is divided, by insulated rail joints I at a highway crossing and by other insulated rail joints 2, 2 spaced to either side of said joints 1, into a pair of insulated track sections, a, a disposed, respectively, at opposite sides of the highway crossing.

Across the end of each track section a remote, from the highway crossing is connected a track battery 3, while across the end of each track section at or near the highway crossing is connected a relay R.

Each relay R includes an electro-magnet 4, an associated armature 5 and a back contact 6. Both armatures and both back contacts are included in the circuit of flasher relay F which controls the flashing of a pair of lamps 1.

Normally the electro-magnets 4 are energized. due to same being in closed circuit through the track sections a, a with the track batteries 3. Therefore, the armatures 5 normally are picked up and are in open circuit relationship to the back contacts 6. Consequently, the circuit of the flasher relay F normally is open and the lamps I normally are inoperative. When, however, a train enters either of the track sections a it shunts the relay R connected with that track section. Thereupon the armature of the shunted relay drops and engages its related back contact 6, thereby closing the circuit of the flasher relay F with the result that the lamps l are alternately flashed.

According to the Fig. l illustration, a train, after passing through one ofthe track sections a and upon entering the other track section, will shunt the relay related to the latter track section and thereby cause the circuit of the flasher relay F to remain closed even after .the train has passed the grade crossing. This is undesirable and is a'primary reason why an interlocking mechanism is used between two relays such as the relays R, R; viz., to assure that a train approaching a highway crossing in either direction will cause the flasher relay to operate, but will .not maintain said relay in operation after the train has passed the highway crossing.

Referring now to Figs. 2 to 12 of thedrawings which, as aforesaid, illustrate an interlocking re- Jlay embodying .an interlocking :mechanism constructed in accordance with the present invention, .lil designates a horizontally disposed panel :of insulating material having mounted thereon,

"upon the number of flasherrelays or other signals or devices that are to be controlled.

The electro-magnets t are mounted on top of the panel it near the rear'thereofand have pole pieces it which extend through said panel and are exposed atthe under side'thereof. The armatures 5 underlie the pole pieces II and at'their rears are pivoted as indicated at! 2, whereby they are upwardly 'swingable by energization of the magnetsA and are free-to drop under the influence of gravity when themagnets l.aredeeneri gized.

Fastened to each armature 5 are blocks '13 of insulating material carrying any desired number of forwardly extendingswitcharms M for cooperationwith-any desired number of back contacts "6 suitably mounted on the panel it and disposed, of course, at'the under side'thereof. When the magnets 4 are energized and the armatures Bare lifted'the switch arms I4 are spaced above the "back contacts 6. When, however, the magnets 4 'are deenergized-and their armatures drop, the

switch arms l l engage theback contacts 6. 'If

desired, front contacts l5 may 'be providedto be engaged by the switcharms 14 when the armatures -5 are'lifted, and said'front contacts, in conjunction with said switcharmsgrnay beused for "the control of any desired circuits. Moreover, while the switch arms M may beof any suitable construction, they preferably are of the known construction illustrated in Fig. 4 for yieldable cooperation with the back contacts 16 and also for yieldable cooperation witlrthe front contacts 55 if the latterare-employed.

"Theswitch arms l4 :and the back contacts 6 are suitably conneritedto binding posts :it and l'l, respectively, mounted "on the panel it at "the topthereof whereby they are readily connectible, through the "instrumentality of said binding posts, with a flasher relay or the like'to be controlled. Similarly, iffront contacts are provided,'they may besuitably connected with other binding posts is mountedonthepanel H! at the top thereof for convenience in connecting said front contacts with desired devices to be con-Y other to the other of said relays. dogs are right and left hand duplicates of each I jacent edges.

held with its leg 28 in an outwardly swung positrolled. Other binding posts It are provided on top of the panel ill for the connection of track circuit conductors with the electro-rnagnets 4.

Suitably secured to the panel it at the under side thereof, between the relays R, R, is a bracket 29 of inverted U-shape including a pair of depending, iorwardly and rearwardly spaced legs 2! between which extend a pair of horizontally disposed, laterally spaced, forwardly and rearwardlyiextending pintles .2-2 which, at their ends, are journaled in said legs.

The bracket 2% may be of one-piece or of any ether suitable construction. Preferably, however, the legs 2! are separate from and are detachably connected with a top, block-like porscrews 24 are employed to fasten said legs to'the ends of said block-like portion 23. Thereby :the legs 21 are detachably connected with the blockliketop portion 21% and, when connected thereto, are held rigidly in assembly therewith. Ascrew passing downwardly through the panel ID into the block-like top portion 23 serves to fasten the bracket 20 tosaid panel, while a polygonallyshaped lug $56 at the top of the block-like portion seated in a polygcnally shaped recess in the under side of the panel ill serves-to hold said bracket against rotation relative to saidpanel.

Mounted on each pintle 22 is a locking dog .21, one related to one of the relays R and the These locking other and ieachrincludes a substantially vertically disposed leg23 depending from the pintle 22, a

substantially horizontally disposed arm 29 extendingoutwardly from the pintle 22 and weighted as indicated at 30, and a substantially horiits top, in spaced relationship to the leg 28, with an upwardly directed nib 32.

The locking dogs 21, under the influence of their weighted arms fit, tend constantly to swing.

inwardly or towardone another, and, unless resuine what may be termed neutral positions, as

illustrated in Fig. 11 of the drawings with their legs 22% disposed substantially vertically and in contact with each other at their inner or ad- On the other hand, if either dog is tion and the other dog is unrestrained against swinging movement under the influence of its weighted arm .29, the latter dog assumes a position with its leg L28 disposed inwardly of itsneutral position and against the leg of the other dog,

as illustrated for example-in Figs. 3 and 9 of the drawings.

If desired, resilient means may be associated with the dogs 2'! to assist the weighted arms 29 in swinging said dogs and to impartthereto quick 5 swinging actions. For example, a light, expan- 'sion coil spring 33 maybe interposed between'the locking dogs toward each other.

Extending forwardly from the armatures 5 of the relays R, R are looking arms 34, 34, respectively, one related to one of the locking dogs 21' and the other to the other of said locking dogs. The forward end portion of each locking arm 34 is disposed outwardly with respect to the leg 28 and in underlying relationship to the weighted arm 29 of its related locking dog 21, and the upper edge of the said forward end portion of each locking arm is disposed to engage the lower edge of the arm 29 of its related looking dog and to swing said dog outwardly from its neutral position when the related armature 5 is lifted responsive to energization of its related electro-magnet 4. Moreover, the toe 3! of each locking dog 27 is of such length that it underlies the lower edge of the forward end portion of the related locking arm 34 when the locking dog is swung outwardly responsive to lifting of the related armature 5, but is disposed inwardly -with respect to the lower edge of the said forward end portion of the related locking arm 3d when the locking dog 2'! is swung inwardly to or beyond its neutral position. Furthermore, the lower edge of the forward end portion of each locking arm 34 is disposed so that it is spaced above the toe 3| of its related locking dog 21 when the locking arm is elevated responsive to lifting of its related armature 5, this spacing be ing suhiciently great so that upon dropping of the arm 34 the locking dog E! is permitted time within which to swing inwardly enough to remove its toe 3! from beneath the locking arm 34 prior to the lower edge of the forward end portion of the locking arm reaching said toe 3!. Accordingly, when either locking arm 34 drops and assuming lack of interference with inward swinging movement of the related locking dog 2'! to or beyond its neutral position, the toe 3! of the locking dog does not interfere with dropping of the locking arm 34 sufficiently to permit the switch arms M to engage the back contacts 6. On the other hand, the spacing of the lower edge of the forward end portion of each locking arm 34 from its related toe 3! when the locking arm is elevated and the locking dog is in an outwardly swung position, is sufiiciently small so that if the locking arm drops and the related locking dog 2'! is not swung inwardly, the locking arm is intercepted in its downward movement by the locking dog toe 3! prior to the switch arms 1 4 engaging the back contacts 6.

Normally, both relays R, R are energized, as aforesaid. Accordingly, both armatures 5 normally are lifted and both locking arms M normally are elevated. Consequenty, both locking dogs 2'! normally are held in outwardly swung positions as illustrated in Figs. 2 and 7 of the drawings. If under such conditions. a train enters either track section a with consequent shunting of the related relay R, the armature 5 of that relay drops, carrying with it the related locking arm 34. As the locking arm 34 drops it releases the related locking dog 21 for inward swinging movement, and since such movement of said dog is unrestrained, it swings quickly inwardly under the influence of its weighted arm 28 and under the influence of the spring 33 if the latter or an equivalent thereof is used, coming to a position of rest against the other locking dog 2'! as illustrated in Fig. 8 of the drawings. Inward swinging movement of the said locking dog occurs so quickly that its toe 3! is removed from the path of downward movement of the locking arm 34 prior to the lower edge of the locking arm reaching the position formerly occupied by said toe. Accordingly, since the armature 5 is not limited in its downward movement by engagement of the locking arm 34 with the toe 3|, said armature continues to drop until its switch arms )1 'mentioned locking dog 21' then is in an inwardly swung position, it restrains the other locking dog against inward swinging movement. Consequently, when the armature of the second mentioned relay R drops, its locking arm 34 is intercepted by the toe 3| of the second mentioned locking dog 27 before said armature has dropped sufficiently to engage its switch arms M with their related back contacts. The relationship of the locking dogs and locking arms then is as illustrated in Fig. 9. tioned locking arm 34 is resting upon the toe of the second mentioned locking dog 21 the nib 32 at the end of said toe is disposed outwardly of said locking arm. Consequently, as long as the second mentioned locking arm remains at rest upon'the toe of its related locking dog, said dog cannot swing inwardly even though the first mentioned locking dog subsequently is swung outwardly. Thus, entering of the second track section a by the train does not result in engagei merit of the switch arms l4 with the back contacts 6 of the relay R related to the second track section.

When the train finally progresses entirely through the first mentioned track section a the normal or original status of the first mentioned relay R is restored. In other words, said first mentioned relay again is energized and its armature 5 and locking arm 34 are lifted, resulting in opening of the flasher relay or other controlled mentioned track section the locking arm 34 of the related relay R remains resting upon the toe 3! of the locking dog 21 of the relay R related to the second mentioned track section. Thus, operation of the flasher or other signal device ceases upon movement of the train from the first track section a into the second track section a.

When finally the train leaves the second track section a the normal or original status of the relay R related to that track section is restored. Accordingly, following passage of a train through both track sections a, a. the original status of the mechanism is restored in readiness to have the recounted operations repeated upon an approaching train moving into and through either track section and subsequently into and through the other track section.

Obviously, any interruption in the circuit of either track section a will result in. closing of the flasher relay or other signal or similar circuit. Obviously, too, in the event of simultaneous interruption of the circuits of both track sections, both of the locking dogs 2? will swing to positions as shown in Fig. 11 of the drawings, with the result that all of the switch arms l4 When the second menwill engage their related back contactsland -assureclosing of the flasher relay or other signal or similar circuit.

Animportant featureofthe present invention resides in the provision or means for mounting the-locking arms on the armatures 5 for vertical adjustments relative thereto to accurately ;position their forwardend portions relative to the locking dogs 21, thereby to insure proper cooperation of said locking arms with said lockiing dogs and proper cooperation of the switch arms M'with the back contacts 6 and with the front contacts it if the latter are used. In the :present instance one of the insulating blocks is ofeach armature 5 extends beyond the inner rend of its related armature and has adjustably mounted thereon the related locking arm 34.

A longitudinally slotted metal block 35 is disposed against the under side of the projecting portion of each block -53, transverselythereof, and is securely clamped against the block it by'a pair of yoke elements =36, 36. The yoke eleiii) 'ments Eli are of substantially'inverted L-shape and include horizontal and vertical arms 31 and fiflyrespectively, the former of which overlie-the relatedolock l3 and the latter of which extend downwardly across the front and the rear edges of the block it, respectively. The arms as are slotted, as indicated at 39, and accommodate the ends of the block 35 which project beyond the forward and the rear edges of the block I3. In the bottom of the block 55 are transverse channels d8 which accommodate bottom, transverse portions 4! of the arms 3l,whereby said arms 38 are interlocked with the block 35. The arms 3? are provided with upstanding ears A2 that are connected together by a clamp screw 43. When the screw 43 is tightened its tendency is to rock the yoke elements 36, 36 upwardly, which results in the block 35 being clamped securely :against the under side of the block is.

The rear end portion of each locking arm 34 extends into the slot of its related block 35and-at its upper edge is provided with a notch 44 wherein is disposed a'fulcrum pin lli which is carried by and extends transversely of the block 35 at a point approximately midway between the ends thereof. The inner end portion of each arm its is of lesser height than the slot in its related lock Accordingly, eacharm 34 1s rockable in a vertical plane about its fulcrum pin 45.

Threaded through thebottom of each block35 is a pair of screws #36, 45, one disposedfcrwardly and the other rearwardly with respect to the fulcrum pin (it. These screws hold the inner end .porti'onof the arm 34 in an elevated position relative to the block 35 and against the fulcrum pin By adjustments of said screws the lock- ,ingarm it obviously may berocked in a vertical :plane about the fulcrum pin '55 to elevateor lower theforward encl'portion-of said locking'armrelative to the block 13 and the armature 5. The screws ili are provided with lock nuts 4.1 to maintain desired adjustments of said screws.

As will be apparent, the blocks 36 may be mounted directly upon the armatures 5 instead of upon blocks, such asthe blocks I3, fastened to said armatures.

Obviously, the blocks 35 may readily and-easily be :mounted on the blocks it by the yoke elements .35.

Obviously, too, very accurate adjustments. of the arms 34 may easily be effected by the adjusting screws lt,-and may be maintained by the lock nuts ill.

Enclosing the mechanisms beneath the panel lll'is abase structure lflwhich serves :as asupport for said panel.

Without further description it is thought that the features and advantages of the invention will be readily apparent to those skilled inv the 1 art, and it will, of course, be understood that changes in the -form, proportion andminor details of construction may be resorted to, without departing from the spirit of the invention and scope ofthe appended claims.

I claim: H I 1. An interlocking relay comprising a pair of electro-magnets, an armature related to each electro-magnet anddisposed to be lifted when its relatedelectro-magnet is energized and .to

drop when its related electro-magnet is .deenersaid locking arms are effective, when lifted by their 'armatures, to hold said locking dogs, in outwardly swung positions relative to each other, a toe on each locking dog disposed in the path of dropping movement of the related locking arm as long as the locking dog remains in an outwardly swung position andeffective, when engaged by the related locking arm, to stop dropping of the'related armature prior to engagement of the'switch arm thereof with its related back contact, said locking dogs being so disposed relative to each other that when either is held in its outwardly swung position by its related looking arm the other, when released by its locking arm, is free to swing inwardly sumciently to withdraw its toe'from the path of dropping movement of the related locking arm, thereby to 6 permit suflicient dropping of the related armature to engage its switch arm with its related back contact, said locking dogs further being so disposed relative to each other that when either 'is in-a released, inwardly swung position it serves to prevent inward swinging of the other, whereby, when the locking arm related to the latter locking dog drops, it is intercepted by theitoe of the latter ocking dog.

2. An interlocking relay asset forth in claim in which the means tending constantly to swing the locking dogs toward each other comprises counterweights carried by the dogs.

3. An'interlocking relay asset forth in claim '1 in which the means'tending constantly to swing the locking dogs toward each other comprises a spring.

l. An interlocking relay as set forth in claim 1 in which the means tending constantly to swing the locking dogs toward each other comprises counterweights carried by the dogs and a cooperating spring.

5. An interlocking relay comprising a pair of electro-magnets, an armature related to each electro-magnet and disposed to be lifted when its related electro-magnet is energized and to drop when its related electro-magnet is deenergized, a switch arm carried by each armature, a back contact related to each switch arm, each switch arm being arranged to engage its back contact when the related armature drops and to be disengaged from its back contact when the related armature is lifted, a locking arm extending forwardly from each armature to be lifted and to drop in harmony therewith, a pair of locking dogs, one related to each locking arm and each pivoted for swinging movement toward and away from the other in a plane at right angles to the plane of movement of the related locking arm, means tending constantly to swing each locking dog inwardly toward the other, each locking dog including'an outwardly extending arm overlying the forward end portion of the related locking arm to be engaged and lifted by the latter when same is lifted, thereby to releasably hold the looking dog in an outwardly swung position, a toe on each locking dog underlying the related looking arm as long as the locking dog remains in an outwardly swung position and efiective, when engaged by the related locking arm to stop dropping of the related armature prior to engagement of the switch arm thereof with its related back contact, said locking dogs being so disposed relative to each other that when either is held in its outwardly swung position by its related locking arm the other, when released by its locking arm, is free to swing inwardly sufiiciently to withdraw its toe from the path of dropping movement of the related locking arm, thereby to permit sufficient dropping of the related armature to engage its switch arm with its related back contact, said locking dogs further being so disposed relative to each other that when either is in a released, inwardly swung position it serves to prevent inward swinging of the other, whereby, when the locking arm related to the latter locking dog drops, it is intercepted by the toe of the latter locking dog.

6. An interlocking relay as set forth in claim 1 in which the toe of each locking dog is provided with a nib for engagement with the related locking arm when the latter is resting upon the toe to prevent inward swinging movement of the related locking arm regardless of the disposition of the other locking dog.

7. An interlocking relay as set forth in claim 5 including means mounting each locking arm on its related armature for adjustable rocking movement in the plane of the arm, thereby to permit accurate predetermining positioning of the forward end portion of each locking arm relative to its related locking dog, and means for rockably adjusting said arm and for maintaining adjustments thereof.

8. An interlocking relay as set forth in claim 5 including a block mounted on each armature, each block having a slot accommodating the rear end portion of the related locking arm, a fulcrum element carried by each block against which the related locking arm is seated for rocking movement in the plane thereof, and a pair of adjusting screws carried by said block, one forwardly and other rearwardly of said fulcrum element, for cooperation with said locking arm to maintain same engaged with said fulcrum element and to adjust same in the plane thereof relative to said block.

FREDERICK T. FEREDAY. 

